Development of a real-time framework between MATLAB and PLC through OPC-UA: A case study of a microgrid energy management system

Abstract

Numerous research laboratories engaged in developing advanced algorithms for controlling Renewable Energy Systems (RES) face constraints due to the absence of specialized equipment for conducting research and experiments. Real-time simulation platforms are well-suited for creating fast or real-time computation models, offering prompt, accurate, and reliable insights for RES control implementation. Nevertheless, the high cost of real-time platforms renders them unaffordable for many laboratories. To address this issue, a cost-effective platform is designed to assist researchers in their activities. The hardware solution involves utilizing a Programmable Logic Control (PLC) to acquire data from diverse sensors and regulate the system through actuators and PI controllers. From a software perspective, a communication framework between MATLAB and the PLC is developed using OPC-UA (Open Platform Communications Unified Architecture) technology. In this paper, the operation and efficiency of the platform have been tested using the Software in the Loop (SIL) technique. The operating model is designed using MATLAB/Simulink to simulate and analyze the appropriate control technique suitable for PLC implementation, whereas the control is executed through Siemens S7–1200 PLC using TIA PORTAL. A visualization interface is established using WinCC-RT. Moreover, this paper presents the platform's design, discusses its application, and illustrates its usage through a case study. Indeed, a complex algorithm developed in MATLAB/Simulink can be automatically executed by any PLC using the designed framework.